1. Field of the Invention
The present invention is directed generally to the control of data networks serving mobile wireless users. In particular, the present invention is directed to systems for policy management in a data network that uses policies to control and charge for mobile data services.
2. Description of the Related Art
Operators of mobile wireless networks have in recent years added data networks to their core networks to allow them to offer data services to their mobile subscribers. However, network operators did not develop unified systems for controlling subscriber access and did not develop a unified way to charge for data services. For example, a network operator may have deployed one control and charging system at a network gateway for general access to data network services and then deployed control and charging systems for each individual service offered. However, this approach has become increasingly burdensome as network operators want to deploy ever more services.
New services could be deployed faster and with less expense if each new service did not require a new controlling and charging system. To meet this need, standards bodies have proposed unified policy and charging control architectures. One example of this effort is the 3GPP R7 Policy Control and Charging Architecture. (See Technical Specification 23.203 V8.0.0 (2007-12), which is incorporated by reference in its entirety). This architecture allows customized control and charging policies to be made and enforced for unique combinations of subscribers and services. Each subscriber may have a unique assortment services that they are allowed to use, at rates unique to the subscriber. Each service may have unique requirements for network resources in order to properly provide the service.
In the 3GPP architecture, control and charging enforcement is performed in a gateway between the carrier's data access network and service providing networks. The gateway has a policy enforcement engine called a Policy Control and Charging Enforcement Function (PCEF) in 3GPP. The PCEF examines packets passing through the gateway and enforces control and charging policy decisions on the packets. These policy decisions are made by a policy decision engine called a Policy Control and Charging Rules Function (PCRF) in 3GPP. The 3GPP does not specify any logical element to perform policy management functions such as creating or locating policies. Having the policy decision engine perform policy management functions would not give consistent results since there would likely be more than one policy decision engine in a network. This could cause conflict and coordination problems. Different policy decision engines could potentially make different policies for the same subscriber using the same service when the subscriber's user device moves from one access network to another, even when both access networks are part of the same overall network, operated by the same business entity. Also, having the policy decision engine perform policy management tasks may overtax the policy decision engines and interfere with the other tasks of the policy decision engines, such as the task of making policy decisions and communicating with policy enforcement engines and application servers about changes to the access network or the service that may require new or modified policy decisions. Additionally, it can be inefficient to have each policy decision engine manage its own set of policies since the same policy may be used by different policy decision engines. Therefore, it can be appreciated that there is a significant need for a new policy management architecture. The present invention provides this and other advantages as will be apparent from the following detailed description and accompanying figures.